Geometry, tacticity and crosslinking in drawn chains

14 questions on Geometry, tacticity and crosslinking in drawn chains from the Polymers chapter: 3 NEET level, 7 JEE Main, 4 JEE Advanced. Each one opens with its answer and solution.

• A short fragment of a polymer chain (four repeat units, end groups shown, substituents drawn with wedges) is drawn. Every adjacent pair of stereocentres has the... NEET level, drawn structure
• A short fragment of a polymer chain (four repeat units, end groups shown, methyl groups drawn with wedges and dashes) is drawn. Which description of the fragmen... JEE Main level, drawn structure
• A short fragment of a polymer chain (five repeat units, end groups shown, substituents drawn with wedges and dashes) is drawn. Which statement about the fragmen... JEE Main level, drawn structure
• A short fragment of a polymer chain (four repeat units, end groups shown, substituents drawn with wedges and dashes) is drawn. Counting each pair of neighbourin... JEE Advanced level, drawn structure
• A short fragment of a polymer chain (two repeat units, end groups shown) is drawn. Which natural polymer does it represent? NEET level, drawn structure
• A short fragment of a polymer chain (three repeat units, end groups shown) is drawn. Compared with the cis isomer of the same constitution (natural rubber), whi... JEE Main level, drawn structure
• A short fragment of a polymer chain (three repeat units, ethyl-type end groups shown) is drawn. Sulfur vulcanisation proceeds mainly through allylic hydrogens. ... JEE Advanced level, drawn structure
• A short fragment of a hydrocarbon rubber chain (two repeat units, end groups shown) is drawn. Select all correct statements about its vulcanisation with sulfur. JEE Main level, drawn structure
• The compound shown is a monomer. Among the structures shown (short fragments of polymer chains, end groups drawn), which one is a fragment of the polymer obtain... NEET level, drawn structure
• A short fragment of a polymer chain (two repeat units, end groups shown) is drawn. Select all correct statements. JEE Main level, drawn structure
• A short fragment of a polymer chain (three repeat units, end groups shown) is drawn. How many of its C=C bonds have the two chain carbons on the same side (cis,... JEE Main level, drawn structure
• A short fragment of a polymer chain (four repeat units, end groups shown, methyl groups drawn with wedges) is drawn. Select all correct statements. JEE Advanced level, drawn structure
• Natural rubber is a polymer of the monomer shown. When rubber is heated with sulfur, the percentage of sulfur determines the product. Which outcome is correct w... JEE Main level, drawn structure
• The compound shown is the first product when a phenol reacts with methanal. Which of the phenols shown, reacting with methanal at its free ortho and para positi... JEE Advanced level, drawn structure